I Wasn't Prepared for This!
by crematosis
Summary: "I can't be pregnant," Tony said. "Forty-three is way too old to be pregnant. Right?" Steve shrugged. "You are still having heats." "Oh god."
1. Chapter 1

A/N: And another Stuckony mpreg prompt. Everyone seems to want these so, here's another one XD

Disclaimer: Again, this was a prompt given to me, asking for omega verse mpreg. I'm just filling in between the lines.

Ordinarily, when they had returned from a week-long mission, Bucky and Steve would have immediately pulled Tony into a hug and several kisses. Steve would babble a lot of sentimental shit about how much they had missed him and how they were never going to leave him again. Bucky was far too practical for that and usually spent post-mission reunions trying to keep Steve kissing Tony so he'd stop talking and the kisses would turn into something more heated and then they'd all end up tangled up in bed together. Because if it weren't for him sometimes, nobody would be getting laid.

But the mission had been long and tedious and far more exhausting than a stakeout without any goddamn action had a right to be. So when they arrived home at 3 a.m. and found Tony fast asleep after a long inventing binge, neither had the heart to wake him. They just curled around him in bed and took comfort in the fact that they were home again.

When Bucky woke up four hours later, Steve was out for his morning run and Tony was still asleep. So he went down to the kitchen to make himself a cup of coffee and some maple bacon because that stuff was the shit, no matter what Tony said.

He had just polished off the plate when Tony strolled in, dressed in a nice suit.

"Meeting today," Tony explained as he stole a sip of Bucky's coffee. "Pepper didn't care that it was the day you two came back from Montana and I'd rather be fucking." He stuck out his tongue. "Oh well. You two will have to make it up to me tonight."

"That we will," Bucky said. He gave Tony's suit an appraising once-over. Something about seeing his mate all dressed up made him just want to strip him down and muss up those neatly ironed clothes. Which he was definitely going to do as soon as Tony came home from his meeting.

Tony leaned in for a kiss and then started towards the coffee machine.

"Wait a minute," Bucky said. He pulled Tony back into his arms and took a deep inhale. "Your scent's changed."

"It's a new cologne," Tony said. "Didn't realize it was that strong."

Bucky shook his head. "That's not it. It's you. You smell different."

Everyone had their own natural scent, but some events could slightly alter a person's body chemistry. And Tony had gone through more of these events than most. As an omega, Tony's scent always got strong and musky when he was in heat. And when he was in distress, which happened far too often for Bucky's liking, it was a sharper, almost sour smell. Bucky was pretty sure the arc reactor had also added a subtle metallic undercurrent to Tony's scent but because he hadn't met him pre-reactor, he couldn't be sure. But Tony's scent had definitely changed after he and Steve had mated with him. A mated omega was marked with his alpha's scent and normally, Bucky should have been bothered by another alpha's scent on his mate, but Steve was his best friend and sharing Tony with him felt so right.

Now that he thought about it, this new layer to Tony's scent was almost like his mark on him. But he didn't feel any of the instinctive anger he would feel at someone else trying to claim his mate. The scent was familiar, nonthreatening. But it was also strange and foreign.

Steve wandered into the kitchen, gulping down the last of his water bottle. His focused look faded into something fond as it landed on Tony. "Hey, babe. We missed you."

Bucky steered Tony in Steve's direction. "Something's happened to our mate's scent," he said.

Steve obligingly leaned in, pressing his face to Tony's neck where his scent would be the strongest.

Tony's mouth twisted in amusement. "Oh, come on. You two have only been gone for a week. You shouldn't be forgetting how I smell already."

Steve's brow furrowed. "No, Bucky's right. You smell…" Steve's eyes went wide. "You smell pregnant."

"That's it," Bucky said. He was smelling the way pregnancy had changed Tony's body chemistry. And the scent of their unborn child. Or children. Bucky had always loved the idea of a houseful of noisy children.

Tony snorted as he reached for a cup of coffee. "Can't be. I'm too way old to get pregnant." He hesitated. "Forty-three is too old, right?"

Steve shrugged. "You're still having heats."

"Oh god," Tony said, backing away from the coffee maker like it was a hostile robot. "I didn't think about this. I mean, I don't think about a lot of things. But this. Never in a million years would I have thought I'd ever end up pregnant. I mean, do we even want children?"

"Yes," Bucky and Steve said at the same time. They grinned at each other.

"Do I want children?" Tony mused. "I don't even know if I'll be a good mother."

"You will," Steve assured him. "I can feel it."

"I can't," Tony said. He rubbed a hand over his stomach. "This doesn't even feel real yet. How the hell can you two tell I'm pregnant before I can?"

Bucky rolled his eyes. "Face it, babe. You're not exactly in tune with your body most days. You know how often Stevie and I have to drag you out of the lab because you don't know your own limits?"

"And you have no idea you're going into heat until you're on the floor whining for us to fill you up because you feel so empty."

"That was a rhetorical question," Tony said. "But thanks for emphasizing what a bad mother I'll be. I can't even take care of myself. How will I take care of a baby?"

"Instinct," Steve said with a shrug.

"Working out great so far, Cap." Tony again reached for Bucky's coffee cup and then seemed to think better of it. "Fuck. How am I going to survive nine whole months without coffee?"

"It'll be worth it." Bucky pulled Tony into his lap and nuzzled against his neck. "Just think of six or seven little Starks running around."

Tony jumped up like he had been burned. "Whoa, whoa, whoa. Let's just start with one baby and see how it goes."

Steve wrapped his arms around Tony's waist, sliding one hand to rest over his stomach. "Don't think you have a choice in the matter."

Tony grumbled, but the slow circular pattern Steve was rubbing over his stomach seemed to soothe him. "So, baby," he said cautiously. "Or babies."

Bucky nodded. "You're going to be a great mother, Tony."

"Well," Tony said thoughtfully. "If I've survived explosions, near-drowning, falling off rooftops, electrocution, stabbings, poisonings, and mind control, I can survive without coffee for almost a year." He smiled shakily. "Right, guys?"

"Right," Bucky said. He stood up to envelope Tony in a hug. He had faith in their omega, but he knew Tony didn't. So he would really need their help to get through this pregnancy.


	2. Chapter 2

After Tony left for Stark Industries, Steve locked himself in the bedroom to read a bunch of parenting articles Jarvis had brought up. Bucky wasn't ready to be that obsessive just yet, so he sparred a little with Natasha and Clint and then settled in to watch one of the Terminator movies Tony loved to hate.

A little after eleven, Bucky heard the sound of the garage door opening over a quiet part of the movie. And the Tony's voice floated up the stairs.

"I'm back! Where's my welcoming committee?"

Bucky immediately paused the movie. It was a rare occasion when Tony managed to get out of work early. He'd probably be in a great mood, with none of the weariness he always seemed to wear after a full day doing business.

Bucky hurried down the stairs, ready to gather his mate into his arms and start loving him like he had promised, but he stopped short a few feet away, clutching his nose. "Oh my god, you reek."

It smelled like Tony had doused himself with that new cologne another twenty times.

"I know, right? They all called the meeting off early because no one could stand to be in the room with me." Tony beamed. "You should have seen the look on Pepper's face. She was so furious." The smile faded. "Oh, shit. She's going to kill me."

Bucky fanned a hand vigorously in front of his face. "It'll serve you right. I'm almost ready to kill you myself if I have to bear this stink much longer. Holy shit, Tony. You must really hate the board if this is the length you'll go to to escape meetings."

Tony frowned, or at least Bucky assumed he did because his eyes were watering too hard for him to really see at the moment.

"I didn't do it just to escape the meeting," Tony said with an air of wounded dignity. "This pregnancy thing is still so new. I didn't even have a chance to tell the rest of the team yet. And I will be damned if the fucking board members are the first to know."

"For fuck's sake. If you just wanted to cover up your scent, you just had to dab on a little extra cologne, not the whole bottle."

"But then I wouldn't have gotten out of the meeting early. Killing two birds with one stone, Buck. And you are happy I'm home early, right?"

Bucky took another big step backwards as Tony came closer. "I'm not touching you until you shower."

Tony huffed and headed into the elevator. Going down to the gym, probably. Because that's where the closest shower was.

Bucky breathed a sigh of relief as soon as he was gone. The faint scent of cologne still lingered in the air, but he was grateful for small mercies. God, he didn't know how Tony managed to go through the day without sneezing to death. One of the benefits to not having super senses, he supposed.

He headed upstairs and poked his head into the bedroom. "Tony's home early."

Steve looked up from his tablet. "Why are you wearing Tony's cologne?"

"Oh, I'm sure the whole Tower is wearing it now."

Steve grimaced. "Really?"

"Really. Our mate will probably want to tell you all about his brilliant plan later."

Steve chewed his bottom lip. "He's taking this whole pregnancy thing really hard, isn't he? Maybe-"

"Hell no. He's actually coming around to the idea. He only coated himself in cologne so the board wouldn't know about the pregnancy before the rest of the team does."

Steve's expression relaxed into fond exasperation. "Only he could think of something like that."  
Bucky nodded. "That's our mate. Stubborn as they come." Which they both loved, of course.

They both looked up as Tony pushed through the door, wearing a cologne-free t-shirt and jeans. "Hope you're happy," he announced, and sprawled face-first onto the bed.

Steve raised an eyebrow at the dramatic display. "You feeling okay, Tony? Worried about the baby?"

Tony shifted his shoulders into something like a shrug. "It still doesn't feel real."

"It will." Steve gently rubbed Tony's back. "Why don't we tell the team tonight? That way you won't have to keep hiding your scent from the board."

Tony lifted his head and shot Steve a sheepish smile. "Bucky told you about that, didn't he?"

"Of course. We tell each other everything."

When dealing with Tony in some of his more impulsive moments, it was always best to keep everybody on the same page.

"Okay," Tony said with a sigh. "Tonight."

Steve rolled Tony onto his back and frowned at the resigned look on the omega's face. "Hey," he said. "It's not going to be a big deal. We just make the announcement and move on. Nobody on the team is going to say anything negative."

"Or I'll have a word with them," Bucky said, pounding his metal fist into his good hand.

Steve rolled his eyes, but Tony's mouth twitched into the beginning of a smile so Bucky didn't care about Steve's disapproval.

"And until then," Tony said, casually bucking his hips upwards. "I can think of a good way to pass the time."

It wasn't the same as tearing Tony out of his suit jacket, but there was still a certain appeal to easing him out of his t-shirt, watching his muscles twitch as Steve ran a hand over his abs. Tony wasn't going to have rock-hard abs for much longer, Bucky reflected. Soon he'd be nice and round with child. And Tony was gorgeous now, but every alpha just had a thing for seeing their mate pregnant.

When he met Steve's eyes, he could tell he was thinking the same thing.

Steve grinned and flicked his thumbs across Tony's nipples. They were already delightfully sensitive spots for Tony, but they were just going to get more sensitive. Bucky couldn't fucking wait.

"Stop teasing me and one of you just fuck me already," Tony growled.

"Nope," Bucky said with a smirk. "It's been a whole week since we've seen you. We've missed touching all this pretty skin."

"I hate you," Tony said with a sigh. But he tilted his head back so Steve could mouth at his collarbone.

Bucky delicately unzipped Tony's pants and ran a hand over his hips and thighs. "It'd be a shame if we didn't take time to properly appreciate how gorgeous you are."

Tony huffed as he wiggled out of his jeans. "It'd be a shame if I had to sit here for another minute hard as hell while you two just coo over me. Seriously, Buck, what's the matter with you? You're usually jumping my bones on sight."

Bucky shrugged. Sex just didn't seem as important at the moment. Touching Tony was all he really wanted to do. But if Tony was going to be this mouthy, he knew where to touch to keep him interested.

He gave Steve a sidelong glance and the blonde nodded, and began peeling the underwear down their omega's hips.

"Fucking finally," Tony said, breathing a sigh of relief.

Huh. Tony hadn't been kidding when he said he was hard as hell. Well, Bucky was going to have to do something about that.

Tony let out a surprised gasp when Bucky wrapped his hand around his cock. "What…what are you-"

"Are you seriously still complaining?" Steve said with a shake of his head.

"Not complaining," Tony said breathlessly. "Other hand, Buck."

Bucky obligingly switched to his metal hand and Tony groaned, deep and throaty, pressing back into the mattress. "Oh, hell yes."

Steve snorted and went back to nipping at Tony's collarbone and rubbing a hand over his hip.

Bucky beamed down at his mate as he twitched and arched, gasped, moaned, groaned, and whimpered and finally came, eyelids fluttering convulsively.

"There. You feel better now?"

"Yes," Tony murmured as he burrowed into the pillow. "It's not fair. You two wear me out so good. I'll probably sleep all the way until dinner."

"Good," Steve said. "I'm sure you need the sleep."

They all knew how poorly Tony tended to sleep when they were out on missions.

Tony flipped him off, but then snuggled further into the bed with a soft sigh, his breathing evening out.

Bucky and Steve exchanged a glance and then Steve reached for his abandoned tablet.

Okay, sure. It wouldn't hurt to take a look at a few baby articles while Tony slept.

Tony woke up a few hours later, reenergized and ravenous. Steve put together a sandwich for him and then they all headed into the den to start movie night.

Everyone else had already gotten there before them, claiming most of the best spots on the couches. But whatever. Bucky was used to sprawling out on the floor in a big pile of pillows and blankets.

Tony sprawled out on the couch between Clint and Natasha, lacing his hands behind his head. "Notice anything different about me?"

Clint shrugged. "No, not really."

Tony frowned. "No? I don't smell any different to you?"

"Oh, come here," Natasha said. She pulled Tony to her side of the couch and sniffed carefully. Her eyes narrowed. "You were wearing too much cologne earlier."

"How do you know?" Tony said. "I washed."

"I still smell a little of it on you. And it's a terrible scent. Never wear it again."

"No problem. I already used up the whole bottle."

Bucky's nose twitched just thinking about it. Blech.

"But other than the cologne, you don't smell anything on me?"

"Nope," Natasha said. She gently pushed him upright.

"Fuck," Tony said. "So I did all that for nothing?" He crossed his arms over his chest and glared in Bucky's direction.

Bucky shrugged. "They're not your mates. They're not as attuned to your scent as we are. And they don't have super senses."

Bruce's eyes flicked between Tony and Bucky. "Mind telling me what's going on?" he asked.

"Tony's pregnant," Steve said cheerfully.

"Or so they say," Tony muttered darkly.

"Now that you mention it," Clint said. "You are looking a little plumper than usual."

Tony threw a cushion at him. "Buck, what did you say you were going to do to anybody talking shit about me?"

Bucky eyed Clint contemplatively and flexed his metal fingers.

"Hey, I'm not talking shit," Clint said quickly. "I'm all for you two getting him knocked up."

"Indeed," Thor said. "A child is cause for celebration. A festive occasion with plates piled high with roasted meats and the mead flowing freely all night long."

"No mead for Tony," Steve said.

"Damnit, that's right," Tony said with a heavy sigh. "No alcohol for nine months."

"You'll live," Steve said, pressing a kiss to Tony's cheek. "I have faith in you."

"So," Clint said. "Movie night. Who votes for Knocked Up?"

This time, Tony wasn't the only one throwing a cushion at Clint.


	3. Chapter 3

Because Tony had shirked that one meeting, Pepper had immediately scheduled meetings everyday for the rest of the week. Normally Bucky would have felt sorry for his mate, but well, he kind of deserved it.

Not that he couldn't still act sympathetic every morning when Tony bitched about having to go into the office. He would rather have Tony at home all day instead of only for a few hours in the evening.

Instead, he was spending all day hanging out with Steve in the gym and then in the den looking over some of the baby books Steve insisted he start reading. And yeah, yeah, Bucky knew it was important that they learn this stuff now so they'd be prepared for when the baby got there. But really, they didn't need to read every damn book Steve managed to get his hands on. It was a baby, not a fucking Ph.d in child psychology.

But he supposed he couldn't blame Steve for going a little overboard. Steve had always wanted a family and for so long, he was convinced it was just never going to happen. So Bucky would forgive him for being a little excited. Hopefully he'd get all the studying out of his system by the time Tony started experiencing more pregnancy symptoms. And then they could both take turns fussing over the omega. Because that was way more fun than reading about pregnancy.

Bucky was pretty burned out by the time Friday afternoon rolled around. But he had the weekend to look forward to, and spending all day with Tony.

He was thrilled when Tony appeared in the den a little after four.

''Hey, hot mama," he said affectionately. He set the book aside and patted his lap. "Come here and let me kiss you."

Tony remained standing. "It's been a long workweek."

"I know," Bucky said with a roll of his eyes. That was why he was encouraging Tony to sit down and relax, let him and Steve take the tension away.

Tony finally settled into the recliner across from the couch."It's funny," he said a little too casually. "Nobody else but the two of you can smell pregnancy on me."

"I'm not exactly surprised," Steve said. "If I remember right, most of the members of your board are in their late fifties, early sixties. And everyone's sense of smell gets a little weaker as they age."

"Pepper didn't notice anything either," Tony said. "And I know she'd immediately start squealing and fussing over me if she knew I was pregnant."

Steve frowned. "Tony, what are you saying?"

"I'm saying that maybe I'm not pregnant."

"Of course you are," Bucky said indignantly. "I can smell-"

Tony put up a hand to stop him. "I just smelled weird to you at first. You didn't think I was pregnant until Steve said it."

Bucky rolled his eyes. "Just because I didn't recognize the scent of pregnancy right away doesn't mean you aren't."

"I even had Jarvis run a couple tests on me. He said it's too early to tell whether I'm pregnant or not. So there's no way the two of you should be able to tell."

"Because we're your mates," Steve said earnestly. "And we have super senses."

Tony shook his head. "I think maybe you two want to be fathers so bad, you talked yourselves into believing it. And I get it, I really do. You'd make a great father, Steve. I mean, what kid wouldn't want Captain America as their dad? I sure did when I was little. And,Buck, baby, I know you want a big family just like you had growing up. But it's not going to happen. I'm just too old to have kids. I think I know my own body better than you do."

Steve rose to his feet. "If that's really how you feel," he said between clenched teeth. He stalked out of the room.

Bucky glared at Tony. "You can be a real asshole sometimes, you know that?"

"I'm not trying to be an asshole. I'm trying to be realistic. I'm just not going to have a baby and it's better that Steve realizes it now before he gets too attached to the idea."

"You don't get to make that call," Bucky said. "And besides, Steve's always been the type who believes it's better to have loved and lost than never loved at all. So if you lose this baby, he'd have rather enjoyed the idea of fatherhood for a little while than be convinced from the beginning the baby wasn't going to live."

"You don't get it," Tony said. "I can't lose what I don't have. I'm not pregnant."

"Yes, you are," Bucky said fiercely. "The sooner you accept it, the better for everyone. I don't want you to keep upsetting Steve."

It was going to fall on him this time to talk Steve out of being pissed and convince him Tony didn't really mean what he said. Or else his two mates were going to be standoffish for days and Bucky sure as hell wasn't going to bed alone.

Steve wasn't down in the gym hitting the punching bags like Bucky had thought. And he wasn't in the kitchen or the den. Finally, Bucky thought to check their shared bedroom.

Steve was sitting on the edge of their bed, staring off into the distance, his eyes looking a little damp.

"Steve?" Bucky said hesitantly. "Are you crying?"

"He doesn't want kids," Steve said miserably.

"He didn't say that."

"He didn't have to. You know Tony wouldn't be trying so hard to prove he's not pregnant if he really wanted a baby. If he wanted this baby, he would immediately feel pregnant and nothing anybody said would convince him otherwise."

"True," Bucky admitted. "But it's not that he doesn't want kids. It's just that he doesn't think he can have them."

"We already told him he's not too old if he's still-"

"No, no, no. You know how Tony gets when he want something, but thinks he can't have it. Remember when we both started falling for him?"

Steve chuckled. "He was so worried that no matter which of us he picked, the other wouldn't be his friend anymore. So he was avoiding both of us in the hopes our feelings would just go away and we'd all just stay friends."

"It's funny now," Bucky said. "But I remember how devastated you were for awhile that you he wanted nothing to do with you anymore."

"Oh, shut up," Steve said. "The way I remember, you were pretty upset, too."

Bucky grinned. "Alright, alright. I admit it. But the point is, Tony's probably freaking out about some aspect of motherhood and it's just easier for him to pretend it isn't happening."

Steve's expression went thoughtful. "Do you think he's worried that if one of us has a baby with him, it'll upset the balance of our relationship?"

"Could be," Bucky said. "We keep telling him he never has to chose between us, but that doesn't mean he really believes that. Maybe he's always been worried something will come along and mess it all up and he's desperately hoping he's not pregnant so everything can stay as it is."

"That's sad," Steve said.

Bucky shrugged. "It's an unusual arrangement."

An omega could have any number of lovers at a given time. But they usually settled down with just one mate. Triads were pretty rare and a stable, long-lasting triad even rarer. Most of them broke up out of jealousy or unequal power dynamics. But most of those alphas weren't best friends beforehand.

"So I guess we just wait this one out," Steve said. "Keep loving him and make sure he realizes this baby isn't going to change things."

"Yep," Bucky said. "It'll be an easy fix."

"And what if we're wrong?" Steve asked quietly. "What if he really isn't pregnant?"

"If we're wrong, we'll know soon enough."

Steve nodded. "Thanks, Buck. It really helps to be able to talk through some of this stuff."

"Hey, that's what friends are for. And if it wasn't for me being the reasonable one all the time, you and Tony would never get your heads out of your asses and figure out your misunderstandings."

Steve shoved him. "And if it wasn't for me teaching you a few things about romance, Tony would have blown you off as a one night stand kind of guy."

Bucky shoved Steve back. "Hey, I'm the one who taught you all those moves, you know."

He remembered how anxious Tony had been the first time he saw them play fighting, worried that they were starting to hate each other. It had taken some time to convince him that was just how their friendship worked. They teased each other, argued, even got into fights sometimes without any ill will. They were almost to the point where they could be just as free and easy with Tony.

The baby was a slight setback in getting Tony to trust them fully, but Bucky was pretty sure they could work things out without too much trouble. He had known from the beginning that Tony had issues with insecurity and it hadn't stopped him from wanting him. And it wasn't going to stop him now.


End file.
